On 2/26/04 18:02, in article ,
"John Alger" wrote:

"John R Weiss" wrote in message
news:S08%b.58709$4o.76896@attbi_s52...
"Tarver Engineering" wrote...

Since my servers seldom get me all the newsgroup messages and
Google.groups can't seem to find the begining of this thread, please
SNIP
realized his error, he applied power, but it was too late. You can, in
fact, hear the engines spooling up just prior to his impact with the
trees in the video we show in class.


So, if I get you correctly, the airplane calculates a Vls based on what it
believes its gross weight is and knows it's Alpha-Max (I presume its stall
AOA). When the pilots tries to fly the jet below the Vls at greater than
Alpha-Max, the aircraft goes into TOGA power which will either power you out
or allow you to hit the ground at full power whichever is more
aerodynamically appropriate. And the system is auto-disabled below 100' so
that you can bring the jet back down to terra-firma without having to
continually be wrestled back into the air in the flare.

Thanks for the education and a very intelligent post.

This thread was started by me and my objections to Airbus' approach to
automation. I think this incident speaks to that objection. Here you have
a complex "Rube Goldberg" approach to protect the pilot from what? Stalling
the aircraft in a circle to land or on a "drive and dive" non-precision
straight-in approach? Why is that necessary?

Here's my point: Had this system not been installed in the aircraft, the
pilot would have been forced to stick and throttle his way through this
(obviously inappropriate) maneuver. Had he simply stuck to flying the jet
instead of relying on automation he obviously didn't understand, he probably
wouldn't have hit the trees.

The aircraft performed as it should have. The pilot simply did not
have an adequate understanding of his aircraft for the manuver he was
doing. He also failed to follow the script. Two things the French
apparently frown upon, expecially when used in combination.

Lesson: if you don't fully understand your aircraft, it can reach out
and bite you someday.


I concur... With a caveat:

The goal of any automation should be to increase safety and decrease work
load. It seems that in this case, automation (because of its complexity)
was a causal factor in the mishap... Not to mention the pilots RELIANCE on
that automation.

Airbus seems to take the approach that pilots need to be kept from flying
outside of the box, so it designs these sorts of "protections" into its
flight control systems. Pilots (being lazy humans by nature) start to rely
on that automation and are lulled into a false sense of security by it.
Makes me wonder in this case if the guy had been flying an airplane that
didn't have alpha floor protection whether he would have tried this stunt...
i.e. "No sweat, the alpha floor protection will save me."

That's the danger in this approach to automation. That's my objection to
it--not to automation as a whole, but in Airbus' approach.

Thanks again, John for a very intelligent and informative post.

I'd like to ask you another question (although again OT for RAMN). Could
you explain how the A320/330 "no greater than 60 degrees AOB" protection
works, where it gets its inputs from, and how it is enabled or disabled?

--Woody

John Alger
A-330 Flight Crew Training Instructor
Former rides: TA-4J, A-7E, EC-130Q and P-3B